JP2003077234A - Bearing mechanism for optical pickup, and disk device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bearing mechanism for an optical pickup by which manufacture cost is reduced and the optical pickup is prevented from vibrating. SOLUTION: The bearing mechanism 700 which makes the optical pickup 250 slide on a guide rod 316 includes a 1st slide part 318 which is provided in an optical pickup base 310 mounted with the optical pickup 250 and slides in contact with the guide rod 316, a holder 702 having a 2nd slide part 704 which is so fitted to the optical pickup base 310 as to be displaced vertically and slides in contact with the guide rod 316, a screw 722 which threadably engages the optical pickup base 310 through the holder 702, and a coil spring 720 which is interposed between the holder 702 and screw 722 and is characterized by that the vertical position of the holder 702 is held with the spring pressure of the coil spring 720.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk device for reproducing and recording a disk recording medium, and more particularly to a bearing mechanism for an optical pickup.

[0002]

2. Description of the Related Art A disk device irradiates a signal surface (recording surface) of a disk-shaped recording medium such as a compact disk or a CD-ROM with a laser beam to form a large number of pits spirally formed on the signal surface. Is a device for reproducing the information recorded by the device by changing the light intensity of the reflected light of the laser beam, such as a CD player or a C player.
A D-ROM drive, a CD-R drive, a DVD drive, etc. are included.

The optical pickup is mounted on a disk device and plays an important role of recording and / or reproducing information on the disk by irradiating the disk with a laser beam and detecting reflected light. During recording and / or reproduction, the disc rotates, and the optical pickup follows a predetermined track of the disc, and thus reciprocates in the radial direction of the disc. At this time, the optical pickup slides on a guide rod extending in the radial direction of the disc.

During operation, that is, at the time of reproducing and / or recording optical information by irradiating a disk-shaped recording medium with laser light, vibration of members involved in recording and reproduction is considered as a cause of impairing the accuracy of reproduction and recording. To be Especially, the vibration generated by the rotation of the disc is transmitted to the base plate on which the turntable that holds the disc is mounted.
This causes vibration of the optical pickup mounted on the base plate. Since the optical pickup slides on the guide rod as described above, it is necessary to provide a slight internal clearance between the guide rod and the guide rod bearing portion of the optical pickup.

However, if this internal gap is left, it causes a larger vibration of the optical pickup.
Such vibration not only hinders the accuracy of reproduction and recording, but also causes a collision sound due to contact between the guide rod and the optical pickup, which hinders disk reproduction. Therefore, various types of bearings for optical pickups have been conventionally provided so as to ensure the smooth movement of the optical pickup and suppress the occurrence of the vibration.

FIG. 5 shows a bearing mechanism 600 of a conventional optical pickup which is an example of this. The bearing mechanism 600 includes a sliding portion 606 of the guide rod and a sliding portion 60.
6, a magnet unit 602 provided on the upper side, and a magnet 60 stored in the magnet unit 602.
4 and a resin clip 608 interposed between the guide rod and the magnet. According to this structure, the guide rod can be attracted to the magnet 604, so that the internal clearance is removed and the vibration at the bearing portion of the guide rod is prevented.

[0007]

However, in the structure of the bearing portion of the conventional optical pickup, there is a problem that a relatively high cost magnet is used and the manufacturing cost is increased.

Further, the magnetic force of the magnet varies, and the magnetic force cannot be adjusted after it is mounted on the bearing portion. Therefore, there is a problem that it is not possible to set the most suitable state for suppressing the occurrence of vibration.

Therefore, an object of the present invention is to provide a bearing mechanism for an optical pickup in which the manufacturing cost is reduced and the vibration of the optical pickup is prevented.

[0010]

In view of the above problems, a bearing mechanism according to the present invention includes a first sliding portion provided on an optical pickup base for mounting an optical pickup and sliding on a guide rod. A holder that is attached to the optical pickup base such that it can be displaced in a direction substantially perpendicular to the optical pickup base, and has a second sliding portion that slides in contact with the guide rod; A bearing mechanism for an optical pickup, comprising a screw screwed through the holder and a coil spring interposed between the holder and the screw, the second sliding portion of the holder being urged by the coil spring. Is pressed against the guide rod, and the pressing force can be adjusted by the screw advancement degree of the screw.

According to the above-mentioned structure, the holder constituting the sliding portion can be moved in the vertical direction by the spring pressure, so that the gap between the bearing portion and the guide rod of the optical pickup, which is a sliding component, can be moved. Smooth sliding is secured.
This also produces an effect that the dimensional error of the guide rod, the parts of the bearing mechanism and the like can be easily absorbed.

Further, by using a coil spring whose size is stable, it is possible to stabilize the pressure applied to the holder by the coil spring. Further, the biasing force of the coil spring can be easily adjusted by adjusting the degree of screw advancement. Further, since the magnet used in the past is not used, the manufacturing cost can be reduced.

The above-described bearing mechanism according to the present invention can be appropriately used in a disk device. A disk device using such a bearing mechanism has a low manufacturing cost, can prevent vibration, and can provide a stable function. Also, unlike leaf springs and torsion coil springs, coil springs prevent defects due to deformation and the like that occur when the disk device is transported, and therefore commercial properties are improved.

Other objects, configurations and effects of the present invention will become more apparent from the following description of the embodiments with reference to the drawings.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, preferred embodiments of a disk device of the present invention and an optical pickup moving mechanism used therein will be described in detail with reference to the accompanying drawings.

FIG. 1 is an exploded perspective view of a disk device according to the present invention. As shown in FIG. 1, the disc device according to the present invention includes a loading chassis 120 and a disc 1.
A disk tray 160 for carrying a disk and a disk tray 160 for carrying a disk that moves in the front-rear direction with respect to the loading chassis 120 and moves between a disk loading / unloading position and a disk playback position, and a loading chassis. Main circuit boards 20 arranged at the lower rear of 120
0 and a turntable 280 on which the disc 100 is placed
And a feed chassis 220 provided with an optical pickup 250 for reproducing and recording the disc 100,
A rotating frame 340 for rotating the feed chassis 220 between a raised position and a lowered position, and a loading cam mechanism 46 for operating the disc tray 160 and the rotating frame 340 provided on the loading chassis.
0 and a casing 360 that accommodates them.

Behind the loading chassis 120,
As shown in FIG. 1, a turntable 2 that supports the disc 100 when the disc 100 rotates and serves as a center of rotation of the disc 100.
A feed chassis 220 including an optical pickup 250 and the like for reproducing and recording 80 and the disc 100 is provided.

More specifically, as shown in FIG. 2, the feed chassis 220 is fixed to a base plate 222 formed of a metal plate material, a turntable rotating spindle motor 240, and a rotary shaft 242 of the spindle motor 240. The optical pickup 250 includes a turntable 280, an optical pickup 250, and an optical pickup moving mechanism 274 as a slide feeding mechanism that moves the optical pickup 250 in the radial direction of the disc 100.

This turntable 240 is a disk 1
00 is sandwiched between a disk clamper (not shown) provided on the outer cover 362, and is rotated together with the rotation of the spindle motor 240. By the rotation, the disc 100 also rotates, and the reproduction / recording of the disc 100 is performed.

Further, this optical pickup moving mechanism 274
As shown in FIG. 2B and FIG. 3, is a sled motor 302 which is provided on the back side of the base plate 222 and includes a DC motor capable of forward / reverse rotation, and a sled motor vertically protruding from the upper surface of the base plate 222. A motor gear 304 (see FIG. 2 and FIG. 3) fixed to the rotating shaft 320 of 302, and a gear A that meshes with the motor gear 304.
306 (see FIG. 3) and a gear B3 having a smaller diameter than the gear A306 integrally formed coaxially on the lower surface of the gear A306.
08 and a rack gear 312 that meshes with this gear B308
And an optical pickup base 31 having a first guide rod bearing portion 266 for the first guide rod 314.
0, a first guide rod 314 slidably supporting the optical pickup base 310 and extending in the front-rear direction of the base plate 222, and a second guide rod 314 of the optical pickup base 310 opposite to the first guide rod 314. Base plate 2 for slidably supporting the bearing portion 330 of the
22 and a second guide rod 316 extending in the front-rear direction. The optical pickup 250 is provided on the optical pickup base 310, and as a result, the optical pickup 250 is mounted on the optical pickup base 3.
With the movement of 10, the disc 100 can be moved in the radial direction. Also, the optical pickup base 310
Are slidably supported by the first guide rod 314 by the first guide rod bearing portion 266.

As shown in FIG. 3, these motor gears 3
04, gear A306, gear B308, rack gear 312
The combination of the above forms a reduction gear mechanism in the optical pickup moving mechanism (slide feed mechanism) 274, decelerates the rotation of the thread motor 302, and then the optical pickup 2
Converted into 50 linear motions. As a result, the optical pickup 250 is configured to be movable in the radial direction of the disc 100 along the first guide rod 314 and the second guide rod 316 by rotating the sled motor 302 in either forward or reverse directions. There is.

More specifically, the sled motor 3 will be described.
02 and the motor gear 304 rotate clockwise as viewed from the upper side in the axial direction, the gear B 308 rotates counterclockwise as viewed from the upper side in the axial direction, and the front of the optical pickup base 310 including the rack gear 312 (direction of the turntable 280). ) Sent to. As a result, the optical pickup 250
The disk 100 moves from the outer peripheral side toward the inner peripheral side. On the other hand, when the thread motor 302 rotates in the opposite direction, the optical pickup 250 moves from the inner circumference side to the outer circumference side of the disc 100.

The optical pickup moving mechanism 274 described above moves the optical pickup 250 in the radial direction of the disc along the first guide rod 314 and the second guide rod 316.

4A and 4B, the second bearing portion 3 of the optical pickup base 310 according to the present invention is shown.
The bearing mechanism 700 provided at 30 is shown in more detail. The bearing mechanism 700 slidably supporting the second guide rod 316 is provided with the second guide rod 316 provided on the optical pickup base 310 formed of hard resin or metal for mounting the optical pickup 250.
A first sliding portion 318 that slides in contact with the optical pickup base 310, and is mounted on the optical pickup base 310 so as to be displaceable in the direction normal to the reference plane of the optical pickup base 310, and slides in contact with the second guide rod 316. A holder 702 having a moving second sliding portion 704 and an optical pickup base 310.
And a coil spring 720 that biases the holder 702 in cooperation with a screw that is screwed through the holder 702.

As shown in FIG. 4B, the second guide rod 316 is positioned between the first sliding portion 318 of the holder 702 and the second sliding portion 704 of the optical pickup base 310. To do. At this time, in order to ensure smooth sliding of the optical pickup, an internal clearance which is a clearance with the second guide rod 316 is set between the two sliding portions 318 and 704. However, this internal clearance will be removed by the bearing mechanism 700 according to the present invention, as will be described later.

The holder 702 is made of resin or the like that provides a desired coefficient of friction, and is shown in FIGS.
As shown in (b), a protrusion 706 having a substantially circular hollow portion for passing the screw 722, a flat portion 708 extending substantially horizontally from the starting point of the protrusion 706, and a substantially vertical direction from the flat portion 708. The extended side wall 710 and the second sliding portion 704 formed by the upper surface of the side wall 710 are included.

The holder 702 preferably substantially includes the second bearing portion 330 of the optical pickup base 310, and the inner surface of the holder 702 contacts the outer surface of the second bearing portion 330.
Rattling in a direction other than the vertical direction after being attached to 0 is prevented.

The diameter of the hollow portion of the protrusion 706 is equal to that of the screw 72.
By making the diameter of the shaft of 2 slightly larger than the diameter of the shaft of the holder 702, it is possible to position the holder 702 with respect to the optical pickup base 310 and prevent rattling after mounting, while the holder 702 does not substantially contact the screw 722 in the vertical direction ( In FIG. 4 (a), the arrow allows the displacement. The height of the protrusion 706 is the same as that of the screw 722.
It is set so that the holder 702 can be displaced in the up-and-down direction while preventing the rattling of the holder 702 in contact with the shaft portion of the holder 702. Therefore, the height of the protruding portion is set so as not to come into contact with the flange portion of the screw 722, but may be ultimately zero.

As shown in FIGS. 4A and 4B, the coil spring 720 is mounted by passing the shaft of the screw 722 through the coil spring 720. When the screw 722 is screwed to the optical pickup base 310, the end of the coil spring 720 is seated on the flange surface of the screw 722, and the other end is in contact with the flat surface 708 of the holder 702. At this time, the amount of elastic deformation of the coil spring 720 is adjusted by adjusting the height of the flange surface of the screw 722.

This adjustment is performed by the optical pickup base 310.
Not only the role of absorbing the allowable manufacturing error of the holder and the holder, but also adjusting the pressing force of the holder 702 on the flat surface portion 708, and as a result, the second guide rod 316 by the second sliding portion 704 of the holder 702. Also plays the role of adjusting the pressure contact force. As described above, since the pressure contact force can be freely adjusted after mounting the holder 702, the sliding resistance of the optical pickup with the second guide rod can be easily adjusted.

As a result, the holder 702 can be maintained at the position where the internal clearance is removed while providing the desired pressure contact force, and the vibration of the optical pickup can be ensured while ensuring the stable movement of the optical pickup. It becomes possible to prevent it.

[0032]

Since the present invention is as described above, it has the following effects. By providing the bearing mechanism according to the present invention, vibration can be prevented while ensuring the stability of sliding of the optical pickup. Further, since the magnet used in the conventional example is not used, the manufacturing cost can be reduced.

Further, by providing the disk device using the bearing mechanism according to the present invention, it is possible to prevent an error in disk reproduction and ensure a stable function.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing the overall configuration of a disk device.

FIG. 2A and FIG. 2B are a top view and a right side view of a feed chassis.

3 is an enlarged bottom view showing a gear mechanism of the feed chassis of FIG. 2. FIG.

FIG. 4 (a) is a detailed side view of the bearing portion 330 according to the preferred embodiment of the present invention, and FIG.
[Fig. 4] is a sectional view taken along line Y-Y of Fig. 4 (a).

FIG. 5 is a diagram schematically showing a bearing mechanism according to a conventional example.

[Explanation of symbols]

100 discs 120 loading chassis 160 disc tray 162 disk mounting part 200 main circuit board 220 feed chassis 222 base plate 226 Right overhang 240 spindle motor 242 rotation axis 250 optical pickup 266 First bearing portion 274 Optical pickup moving mechanism 280 turntable 302 thread motor 304 motor gear 306 Gear A 308 Gear B 310 Optical pickup base 312 rack gear 314 First guide rod 316 Second guide rod 318 First sliding portion 320 rotation axis 330 Second bearing portion 340 rotating frame 360 casing 362 outer cover 460 loading cam mechanism 600 bearing mechanism 602 magnet unit 604 magnet 606 Sliding part 608 resin clip 700 bearing mechanism 702 holder 704 Second sliding part 706 protrusion 708 plane part 710 Side wall 720 coil spring 722 screw

Claims (2)

[Claims] 1. A first sliding portion, which is provided on an optical pickup base on which an optical pickup is mounted and slides in contact with a guide rod, and the optical pickup base, which is substantially vertical to the optical pickup base. A holder that has a second sliding portion that is mounted so as to be displaceable to and that slides in contact with the guide rod; a screw that is screwed to the optical pickup base via the holder; A bearing mechanism for an optical pickup comprising a coil spring interposed therebetween, wherein the second sliding portion of the holder is pressed against the guide rod by the biasing force of the coil spring, and the pressing force is applied to the screw. A bearing mechanism having a structure that can be adjusted by the degree of screw advancement. 2. A disk device comprising the bearing mechanism according to claim 1.